Mixing apparatus

Abstract

An apparatus for the mixing of materials such as synthetic polymers and their additives. The apparatus comprises a casing which surrounds a cylindrical rotor. A series of groove rings and spacer rings are axially arranged on the rotor and in the casing. The grooves formed on the peripheral surface of the groove rings are circumferentially separated by shearing lands and are bound along their longitudinal side faces by the side faces of the alternately arranged spacer rings. In assembly, the grooves formed in the rotor groove rings are arranged in a partially overlapping, axially displaced relationship with respect to the radially opposed grooves formed on casing groove rings.

What is claimed is: 
     
       1. An apparatus for mixing materials such as synthetic polymers and their additives, said apparatus comprising: a casing surrounding a cylindrical rotor,   a series of profile rings consisting of groove rings and spacer rings axially arranged in alternating sequence on said rotor and is said casing which are in snug axial engagement with one another,   said groove rings having grooves formed in their peripheral working surfaces which are circumferentially separated by shearing lands and which are limited in an axial direction by the end surfaces of said spacer rings abutting upon the end surfaces of said groove rings, said shearing lands and end surfaces defining said grooves as a series of individual closed chambers, and   said grooves formed on said rotor groove rings being arranged in a partially overlapping, axially displaced relationship with respect to the radially opposed grooves formed on said casing groove rings so that the material will flow between said overlapping rotor and casing closed groove chambers thereby causing repeated dispersal of the material as it moves through the mixing apparatus.   
     
     
       2. The mixing apparatus of claim 1 wherein said grooves are formed in said groove rings in an axial direction with the ends of said grooves forming side surfaces having an equilateral trapezoid shape with respect to each other. 
     
     
       3. The mixing apparatus of claim 1 wherein said grooves are formed in said groove rings in an oblique direction with respect to the axis of said rings thereby providing a conveying effect to said materials. 
     
     
       4. The mixing apparatus of claim 1 wherein said grooves have a material entry zone and a material exit zone, the groove entry zones of the grooves formed in the rotor groove rings being arranged opposite to the groove exit zones of the grooves formed in the casing groove rings and, in a corresponding manner, the groove entry zones of the grooves formed in the casing groove rings being arranged opposite the groove exit zones of the grooves formed in the rotor groove rings. 
     
     
       5. The mixing apparatus of claim 1 wherein said motor and casing are connected to the ejection end of a screw extruder, the central root section of said screw extruder being arranged to rotatably drive said rotor. 
     
     
       6. The mixing apparatus of claim 1 wherein said spacer rings further comprise a special spacer ring mounted in the casing having a bore formed through it in a radial direction which permits said additives to be introduced to the material as it is being mixed.